The present invention relates to thermoformable sheet materials usable in manufacture of shoe and skate braces, counters and box toes; vehicle headliners, rear decks and trunk compartments; and other like complex shaped parts with a significant strength specification, including such sheet materials with or without an applied, adhesive on one or both surfaces thereof, for laminating to other materials (e.g. shoe counters or box toe laminated to the shoe upper).
Materials of this general class have been made for the last fifty years. The current state of the art includes a segment of higher stiffness and low cost occupied by nonwoven fabrics saturated with polystyrene (i.e. saturated with a latex containing styrene that is dried to form a polystyrene matrix).sup.1 and another segment occupied by laminates of extruded resin and nonwoven fabric and hybrids, e.g. where a fabric, laminated to a resin, is saturated with polystyrene. FNT 1 Other synthetic or cellulosic materials are also employed in such applications.
It is also known in connection with materials usable in carpets, headliners and trunks to densify and self bond all or portions of a nonwoven fiber mass by use of mixed higher and lower melting point fibers and heating between the two melting points so that the lower melting point fiber softens and rehardens as dispersed consolidated masses that lock in many crossover points of the higher melting fiber.
It is an object of the present invention to provide a thermoformable sheet form material of enhanced flexibility and resilience compared to the state of the art saturated fabric and resin laminate materials while affording the stiffness and strength of such state of the art materials.
It is a further object of the invention to provide a material that affords reliable, easily achieved design properties and is produceable at high rates and low cost, consistent with the foregoing objects.
It is a further object of the invention to provide an environmentally preferred material consistent with the foregoing objects.
Other objects, features and advantages will be apparent from the following detailed description of preferred embodiments taken in conjunction with the accompanying drawings in which: